Chatterless oil and process of producing the same



No Drawing.

Patented Nov. 11,1930

UNITED STATES PATENT OFFICE THEODORE W. DOELL, 0]! BERKELEY,

AND EDWIN N. KLEMGARD, OF ALBANY, CALI- FORNIA, ASSIGNORS TO STANDARD OIL COMPANY OF CALIFORNIA, OF SAN FRAN- CISCO, CALIFORNIA, A CORPORATION OF DELAWARE I CHATTERLESS OIL AND PROCESS OF PRODUCING THE SAME This invention relates to a lubricating oil for use in internal combustion engines and although it can be used with any type of internal combustion engine, it is particularly.

adapted for use with certain well known automobiles having a planetary transmission controlled by metallic bands having fabric 11nin s. I

In automobiles of this type, the crank case is ordinarily in open communication with the transmission ease, thus permitting the oilm the crank case to enter the transmission case. A single type of lubricant is used for lubricating both the engine and the transmission, although the lubrication requirements for these two parts of the automobile are quite different. An ordinary oil suitable for engine lubrication will often cause the linings of the transmission 'bands to become brittle and acquire a hard, glazed surface wh ch causes the bands alternately to seize and sllp, thus causing a vibration of the entire car, commonly known as chattering. Chattering is encountered mainly when operating the foot brake, and to a lesser extent, by seizure of the reverse and low speed bands. The object of the present invention is .to provide a lubricating oil which will substantially eliminate chattering.

Another object is to provide an oil which is stable in service and storage.

Another object is to provide an oil which will not cause sticking or gummlng of the piston rings or valve stems. t

Another object is to produce an oil wh ch will not give excessive carbon formation which leads to cylinder wear. Various lubricating oils have been made heretofore for the purpose of preventing the chattering of planetary transmisslon bands but the desired result has usually been obtained at the expense of other desirable qualities of the oil. Some nonchattering oils de compose upon standing in storage. Others deposit an excessive amount of carbon on the pistons and cylinder head, cause gummlng of the piston rings, increase the 'oil consumption and reduce the available horsepower of the motor. Other non-chattering oils have unsatisfactory viscosity curves, being too vis- Appliration filed October 12, 1926. Serial No. 141,246.

cous at low temperatures. Some such oils have a tendency to foam while others lose a part of their oily quality.

A common. method of preparing nonchattering oils is to mix a small quantity of animal or vegetable oil with a-larger quantity of suitable mineral lubricating oil. Another method is to mix with the mineral oil various amounts of certain soaps, such as aluminum or sodium-soaps. Another method is to mix a small amount of mineral castor oil with a larger amount of mineral oil. All of these methods are unsatisfactory largely for one or another of the reasons hereinbefore enumerated.

The present invention comprises a nonchattering oil in which the foregoing disadvantages are. overcome. This lubricant is made by mixing a considerable quantity of a suitable mineral lubricating oil with a small amount of lead soap base. There are several lead soaps which may be used for the base in compounding with mineral oils to give the desired non-chattering lubricant such, for example, as lead oleates, linoleates, and ricinoleates. The lead salts of the higher saturated fatty acids are nearly insoluble in mineral oil, whereas lead oleate, linoleate, ricinoleate or, in short, the lead salts of the most frequently occurring unsaturated acids are soluble and adaptable to the production of chatter-preventing oils. While it is most convenient and economical to make use of oleic acid in the preparation of the lead soap base, it is possible that triglycerides (whole fats or fatty oils) such as triolein, linseed oil, castor oil, etc., could be used. It has been found that while the addition of a small amount of lead soap to a lubricating oil practically eliminates the chattering of-planetary transmission bands, the oils thus compounded are not always stable and when subjected to the presence of moisture, either during use in the machine or by exposure to moist atmosphere during long periods of storage, there is a tendency for the soap base to separate and settle to the bottom of the mixture. We have found that the stability of the compounded lubricant or oil may be greatly increased by the addition of a small amount of a salt of a petroleum acid. By the term petroleum acid as used herein, we mean naphthenlc acids and those (napthenic-like) organic acids found in petroleum oils and which may be extracted by washing oils with alkali solutions, thereby forming alkali salts of these acids (said salts remaining in the wash water) and then liberating these petroleum acids by treating solutions of alkali salts of petroleum acids with free mineral aclds. \Vhile these petroleum acids probably contain various hydrocarbons and organic acids, we believe that they are principally of the type conforming to the formula C H O where n has a value of approximately 6 to 24. These acids have sometimes been called naphthenic acids, although it has not been definitely established that they are true na hthenic acids. I

8f the various salts of petroleum acids,

' we prefer to use the lead salt, and more par-J added to a mineral oil.

ticularly the lead salt'which we shall term the lead naphthenate, or the lead salt of a naphthenic acid. We have also found that the most effective results are obtained when the lead soap and the lead salt or naphthenate are both prepared simultaneously by precipitation from a solution containing a naphthenate and the desired soap. Thus, when using the oleate of lead, we prepare what may-be termed a lead-oleo-naphthenate. What we term a lead-oleo-naphthenate is evidently a complex salt, as a lead oleate anda lead naphthenate prepared separately and then mixed together and with a mineral oil does not produce a lubricating oil of the adhering, stable, chatterless characteristics which are produced when the two lead salts or lead oleate and lead salts of naphthenic acids are precipitated together and then The naphthenate alone does not appear to improve the characteristics of the lubricating oil but the complex ordouble or mixed salt above described is very effective, particularly if the naphthenate therein is not present in sufficient quantity to materially reduce the efliciency of the compound. p

In order to prepare the lead-oleo-naphthenate, a mixture of commercial oleic acid and naphthenic acid is saponified with. lye such, for example, as .sodium or potassium hydroxide, until a faint alkaline reaction can be observed. A small amount of the free acid mixture is then added to bring the batch to a very slightly acid condition: The solution of sodium naphthenate and oleate is then brought in contact with a solution of lead acetate or other soluble lead salt for the production of a precipitate containing the desired lead oleate soap (or other lead soap) mixed with lead naphthenate (or other oil soluble salt of petroleum acid). While it is not known that such is the case, it is probable that At" first the solution a complex or double compound is formed which, as stated above, we term lead-oleonaphthenate. The addition of lead acetate is continued so long as precipitation of the insoluble lead soap occurs. Obviously, there is no formula for the production of the lead soap owing to the irregularities due to variations in stocks used. In order to enable those skilled in the art to practice our invention, we give the following description of a preferred process for the manufacture of a desired soap base. v

The petroleum acid employed in the process. and which we shall term naphthenie acid, is preferably derived from neutralization of gas oil with lye. In order to illustrate the reaction occurring, the following equation is given in which the formula-C H COOH is used as a typical naphthenic acid:

' 0 E15000H+NaOH=C 3H 5OOON.+H1O

Approximately equal volumes of commercial ole1c acid and naphthenic acids may be mixed in a suitable kettle'or vat together with 'a suitable quantity of fresh water, for ex ample four volumes of water to one volume of the naphthenic acids used. Steam is applied and whenthe temperature has reached approximately 125 F.,.the lye is allowed to run into the acid-water mixture. During the operation, the temperature is raised to approximately 180 F. Towards the end of the neutralization, great care must be exercised not to overreach "the neutralization point. This may be done by bringing a drop of the soap solution together with a drop of phenolphthalein solution upon a glass or porcelain plate. As soon as a faint pink color appears at the. touching point of the two liquids. the reaction is completed. Approximately per cent. by weight of the total amount of mixed acids, in addition to the above, are added to the mixture to be sure that the mass is just faintly on the acid side.

The formation of the soda soap of oleic naphthenic'acid is believed to simultaneously take place in accordance with the following equation: CnHnCOOH-I-CnHuCOOEH-ZNBOH== C17HaCOONa-l-CnHuCOONa-l-flIzO After having ascertained that the temperature is still about 180 F., the lead acetate solutionis allowed to flow into the solution of sodium oleate and sodium naphthenate.

turns milky, becomesbrownish later on, and seems to thickmass is stopped and on up. Finally lumps begin to appear. The lumps, becoming heavier, sink to the bottom and the supernatant liquor begins to clear up. At this point, the addition of the lead acetate solution should be carefully watched and stopped as soon as there appears to be no more precipitate formed at the point where the lead acetate solution drops into the soap solution. A sample of the nearly clear supernatant liquor is then taken from the kettle, and a few drops of sodium chromate solution are added. A heavy yellow precipitate indicates that all the organic acids are carried down in the form of their lead soaps. During the whole operation, the temperature is preferably kept at about 180 F. a

As soon as the precipitation of the leadoleo-naphthenate is finished, agitation of the the mixture allowed to settle for about one-half hour.

The conversion of the sodium salts of oleic and naphthenic acid to the lead soap naphthenate or lead-oleo-naphthenate: is believed to take place in accordance with the follow- The supernatant liquor is then siphoned oif, or pumped off by means of a skimming pump. An excess of fresh water is added to the lead soaps, agitated, and heated to about 180 F. As soon as the temperature .water is added.

has reached this point, agitation is stoppedand themass allowed to settle. The water is then drawn off as before andthe washing repeated with water, heated and agitated,. and again allowed to settle. The wash water is drawn oft'again. and an excess of fresh This time no heat is applied but' the soaps are agitated with the cold water and allowed to cool to about F. Agitation is 'then stopped and the now thoroughly washed lead soaps are. allowed to settle. The last wash water is then skimmed oif as completely as possible.

The soap mass is now ready to be dried. This is done by heating it by means of a steam coil or steam jacket. When the temperature reaches about 215 F., foaming sets in which increases the volume of the soap about 4 times. As soon as the temperature reaches approximately 225 F.. foaming ceases and the soap begins to become clearer. The mass is then heated as quickly as possible to about 300 F. to be certain that the last traces of water are removed. The soap mass is drawn into open-head iron drums and is ready for use. p

The soap mass should be drawn as quickly as possible after having been dried, as prolonged heating darkens it considerably, thus tending to impair the color of the lubricating oil with which it is mixed.

While no fixed formula for the lead soap n ass can be given, it will, when produced by the foregoing process, be found to approximate the following analysis:

The actual average percent. yield from the net formula is 73.3 per cent.

In order to prepare from this soap mass a soap base which maybe used to compound with a lubricating oil so as to form a nonchattering lubricant ready for use in the machine, about 25 per cent. by weight of the drylead-oleo-naphthenate, produced in accordance with the above procedure, is dissolved in approximately 75 per cent. by weight of a suitable minerallubricating oil, the soap mass being stirredinto the oil during gentle heating of the same to a temperature not exceeding about F.

The finished non-chattering lubricating oil is then prepared by adding approximately 3 per cent. by weight of the lead soap base to approximately of a suitable mineral lubricating oil, thus giving a final solution containing approximately per cent. by weight of the lead soap. The lubricating oil referred to herein 97 per cent. byweight may be any of the usual and well known types of oils used for the lubrication of automobile engines.

It should be pointed out that the product produced is a lubricating oil containing a small percentage of lead-oleo-naphthenate dissolved therein and-is not tobe considered similar to products produced by addinglarge percentages of lead orother soaps to lubricating oils. Where a. large percentage of lead or other soaps are added to lubricating oils. the resulting mass emulsified,

into a semi-solid mass or grease, a product distinctly diiferent from that produced by the present invention. In the present invention, the lubricating oil contains less than sufiicient soap base to solidify the mass or form a grease. In fact, the amount of soap base added is sufiiciently low as to have substantially no efli'ect upon the viscosity of the lubricating oil.

Obviously the proportions and methods described in the foregoing example of a preferred embodiment of the invention may be varied considerably, and the invention is not to be considered as limited to the exact figures set forth herein but is of the scope covered by the follow ng claims.

We claim:

1. A process of )roducing a chatterless lu brica-ting oil whic comprises dissolving in a mineral lubricating oil a small amount of a complex lead salt of a petroleum acid,

which acid is obtained by treating a petroleum oil with an alkali,, withdrawing the alkali solution and treating the same with an acid of greater strength than that of the acid desired, with a lead soap of unsaturated fatty acid.

' 2. A process of reducing a chatterless lubricating oil whic comprises dissolving in a mineral lubricating oil a small amount of a complex lead salt of oleic and petroleum acid, whlch petroleum acid is obtained by treating a petroleum oil with an alkali,'withdrawing the alkali solution and treating the same with an acid'of greater strength than thatof the acid desired.

3. A process of producing a chatterless oil which comprises simultaneously precipitat ing from a solution of alkali salts of fatty and naphthenic-like acids, by means of a which comprises simultaneously water soluble lead salt, a complex lead com-' pound and thereafter dissolving a small amount of said material in a mineral lubricatin oil.

4. process of producing a chatterless oil ing from a solution of alkali sa ts of unsaturated fatty acids' and petroleum acids, which petroleum acids are obtained by treating a petroleum oil with an alkali, withdrawing the alkali solution and treating same with an acid of greater strength than that of the acid desired, by means of a water solublelead salt, a complex lead compound, and thereafter dissolving a smallamount of said material in a mineral lubricating oil.-

5. A process of producing a chatterlesslubricatingoil which comprises simultaneously precipitating from a solution of alkali salts and oleic acids and naphthenic acids, by means of a water soluble lead salt, a complex lead compound, and dissolving said ma terials in a mineral lubricating oil.

6. A lubricating oil comprising a mineral precipitatof mineral lubricating oil having mixed therewith, in amounts tially affect the viscosity of the mineral oil, a mixture consi'stingof a leadsalt of an unsaturated acid and lead salts of naphthenic acid in amounts suflicienttoprevent separation of the lead soap from the mineral oil in the presence of moisture.

9. A lubricating oil comprising a mineral lubricating oil containing a lead soap of an unsaturated fatty acid and a lead salt of napthe'nic-like acid.

10. A chatterless lubricating oil com rising a mineral lubricating oil having disso ved therein a lead soap of oleic acid and a lead salt of a napthenic-like acid.

. 11. A lubricating oil' having dissolved therein a complex lead salt of unsaturated fatty acids and napthenic-like acids. I 12. In a process of producing a chatterless lubricating oil, the step of simultaneously precipitating from a solution of alkali salts of unsaturated fags and naptheniclike acids, a complex 1 soap by means of a water soluble lead salt.

13. In a process'of producing a chatterless lubricating oil, the step of simultaneously precipitating -a complex lead soap by means of a water soluble lead 'salt from a solution of alkali salts of oleic and napthenic like acids.

Calif, this 30th day insuficient to substan mixed petroleum acids; and unsaturated fatty acids, simultaneously combining such acids with an alkali, addin an" aqueous lead salt solution to form lea washing and drying such salts and then add- -ing a small quantity thereof to a mineral lubricating oil.

8. A lubricating oil comprising a mixture salts of said acids, 

